How to Control Speed in a 12 Volt Electric Motor

Speed control with a 12 volt electric motor depends on what type of motor is being used. Most 12 volt motors are of the DC, or direct current, type -- often used for pumps, fans, and toys. There are two primary ways to control a DC motor's speed: change the field coil voltage or change the armature voltage. The field coil is the non rotating coil that surrounds the armature. The armature is the rotating coil which is connected to the motor's rotating shaft.

Things You'll Need

• 12 volt DC motor
• Variable 12 volt power supply
• Jumper wires with alligator clips

Instructions

1. Plug in the 12 volt DC power supply. Connect the positive terminal of the DC motor to the positive terminal of the DC power supply using one of the jumpers.

2. Connect the negative terminal of the DC power supply to the negative terminal of the motor. Turn the power supply on and slowly increase the power supply output voltage to 12 volts.

3. Watch the motor speed. Once the rotor starts to rotate, the rotor speed will increase as the power supply voltage is increased.

References

• Oddparts: Overview of Motor Types Tutorial